自定义ViewModelStoreOwner创建HiltViewModel崩溃的排查与解决

我有一段可正常运行的Compose代码：

val pagerVM = hiltViewModel(
    creationCallback = { factory: JourneySummaryPagerViewModel.Factory ->
        factory.create(selectedIndex.value)
    },
    key = viewModel.journeys.toString()
)
JourneySummaryPager(
    viewModel = pagerVM
)

出于项目需求，我需要将ViewModel的生成限定在特定的ViewModelStoreOwner范围内，因此编写了如下代码：

val storeOwner = object : ViewModelStoreOwner {
    override val viewModelStore = ViewModelStore()
}

CompositionLocalProvider(value = LocalViewModelStoreOwner provides storeOwner) {

    val pagerVM = hiltViewModel(
        creationCallback = { factory: JourneySummaryPagerViewModel.Factory ->
            factory.create(selectedIndex.value)
        },
        key = viewModel.journeys.toString()
    )
    JourneySummaryPager(
        viewModel = pagerVM
    )
}

但启动应用时出现崩溃，报错信息如下：

java.lang.RuntimeException: Cannot create an instance of class
fr.tisseo.android.screen.map.header.journey.journeySummaryPager.JourneySummaryPagerViewModel
at
androidx.lifecycle.viewmodel.internal.JvmViewModelProviders.createViewModel(JvmViewModelProviders.kt:40)

请问如何让Hilt能够通过自定义ViewModelStoreOwner创建我的ViewModel？

崩溃的核心原因是自定义的ViewModelStoreOwner没有关联Hilt的依赖注入上下文，Hilt无法在这个自定义实例中获取ViewModel所需的依赖与Factory。解决步骤如下：

1. 定义Hilt EntryPoint获取ViewModelFactory
   先创建一个EntryPoint接口，用于从Hilt组件中获取ViewModelFactory：

   @InstallIn(SingletonComponent::class) // 根据你的实际依赖范围调整，比如ActivityComponent/FragmentComponent
   @EntryPoint
   interface ViewModelFactoryEntryPoint {
       fun viewModelFactory(): ViewModelProvider.Factory
   }
   

2. 实现带Hilt支持的自定义ViewModelStoreOwner
   让自定义的ViewModelStoreOwner同时实现HasDefaultViewModelProviderFactory接口，绑定Hilt提供的ViewModelFactory：

   // 从当前应用上下文获取Hilt EntryPoint
   val entryPoint = EntryPointAccessors.fromApplication(
       LocalContext.current.applicationContext,
       ViewModelFactoryEntryPoint::class.java
   )
   val hiltViewModelFactory = entryPoint.viewModelFactory()
   
   val storeOwner = object : ViewModelStoreOwner, HasDefaultViewModelProviderFactory {
       override val viewModelStore = ViewModelStore()
       override val defaultViewModelProviderFactory: ViewModelProvider.Factory
           get() = hiltViewModelFactory
   }
   

3. 保持原有调用逻辑即可
   现在在CompositionLocalProvider内部调用hiltViewModel时，就能通过自定义storeOwner的Hilt Factory正确创建ViewModel：

   CompositionLocalProvider(value = LocalViewModelStoreOwner provides storeOwner) {
       val pagerVM = hiltViewModel(
           creationCallback = { factory: JourneySummaryPagerViewModel.Factory ->
               factory.create(selectedIndex.value)
           },
           key = viewModel.journeys.toString()
       )
       JourneySummaryPager(viewModel = pagerVM)
   }
   

额外注意事项 #

• 确保JourneySummaryPagerViewModel及其Factory是由Hilt管理的（比如使用@HiltViewModel注解，Factory由Hilt自动生成）
• 自定义的ViewModelStoreOwner需要在合适的时机调用viewModelStore.clear()，避免内存泄漏

内容的提问来源于stack exchange，提问作者Kevin ABRIOUX